Throughout this series, we've talked about preparing your vehicle's trailer hitch and wiring, determining weights and towing capabilities, and how to hook up and tow. The last area to cover is improvements to your tow vehicle. There are modifications you can make that can yield more engine power and protect your tow vehicle from the stresses of towing.
WARNING: Many of these modifications will void the manufacturer's warranty on a new vehicle. Many dealer service centers will refuse to work on any vehicle that has been modified from the factory design in any way. Check your warranty and check with your dealer before you make any modifications to your tow vehicle.
Before you set out to modify your tow vehicle, you need to understand that when you make changes to the factory design, you're taking responsibility for those changes. If you don't do the work to professional standards, you can damage or even ruin your vehicle. If you doubt your ability to get the work done right, you should take your tow vehicle to a good service center and ask their advice and help.
Also, the addition of performance components may give you more engine power, but you should not exceed your vehicle's factory towing capacity specifications. Think of these modifications as increasing your vehicle's margin of safety, not increasing its capabilities.
Many pickup trucks, vans, SUVs, and RVs can be purchased with optional "Trailering" and "Camper" packages. It's always a good idea to purchase these options, because they mean that the automaker will install heavy-duty parts on your vehicle with a full factory warranty. Trailering and camper packages generally include an engine oil cooler, more capable radiator, a more advantageous rear axle ratio, heavy-duty suspension, and installed trailer wiring. In some cases, a trailer brake controller is also included.
If you're buying a vehicle specifically for towing, consider buying a 2WD model. Trucks and SUVs with AWD or 4WD are heavier and sometimes the transmission/transfer case parts have a lower towing capability than the comparable 2WD units. If you know that your towing will all be done on pavement, it's generally better to avoid 4WD.
Aftermarket Performance Upgrades
Some trailer dealers also offer performance upgrades for tow vehicles. These devices are not legal in every state or municipality, so check your local laws first to be sure. If your vehicle is subject to emissions inspection and testing, these devices can also make your vehicle fail the test. Again, check your local laws to be sure.
Some of the most common upgrades available are free-flowing "cat-back" exhaust systems and fresh air intakes with free-flowing air filters. Installed together, these parts can increase horsepower and torque by about 10% by opening up airflow through the engine.
For vehicles made in the last 10 years, you can also purchase "reflash" or "chip" engine programmers. These change the way the engine control computer behaves and can deliver more torque and horsepower. For a tow vehicle, always choose the program that is listed as being safe for towing. Sometimes these programs reduce your total towing capacity in exchange for increased performance at lighter loads, so do your research carefully.
Some older automatic transmissions can be retrofitted with "RV" parts that change shift points and help your vehicle handle heavy loads. These generally hold each gear longer to keep your engine solidly in its power band before shifting to a higher gear, and this might feel strange, especially when you're not towing.
A larger radiator and a set of engine oil and transmission lubricant coolers can really help with towing. Under increased stress, your engine and transmission will run hotter, and anything you can do to keep those temperatures down will help prolong the life of your tow vehicle. Most manufacturers have a factory option or dealer-installed option for these parts, and you should use those parts if at all possible.
Another aftermarket improvement you can make is to add suspension capability. The commonly-available overload springs and coil spring assists are not worth very much. It's only a little more expensive, but a lot more effective, to take your tow vehicle to a reputable spring and suspension shop and have heavy-duty springs installed. For rear leaf springs, as commonly found on full-size pickup trucks and vans, the spring shop can install an extra leaf or two and re-arch the springs. Heavy-duty replacement coil springs for the front suspension are often available as well.
Be sure that you also outfit your vehicle with the best possible shock absorbers for trailering. Good shocks keep your vehicle stable and reduce sway, especially when your trailing rig hits potholes or rough pavement.
With a bit of work, you can outfit your tow vehicle for maximum comfort and prolong its working life at the same time.